Two Diffraction Gratings - Rotation

In summary, the rectangular patterns generated by the laser pointer in the youtube video are created by two diffraction gratings that are rotated relative to each other. This rotation angle determines the pattern formed, with a 90 degree rotation resulting in the light splitting into three diverging rays that are then split again at the second diffraction grating layer. The image attached also shows the use of a single axis diffraction grating, while the video features a double axis diffraction. The polarization of the laser may also play a role in the pattern formation.
  • #1
Hunter235711
14
1
Can someone explain how the laser pointer is generating the rectangular patterns shown in this youtube video?

I assume that there are just two diffraction gratings that are rotated relative to each other, but could someone explain mathematically how to predict what pattern is formed for different rotation angles?

Thanks,
Hunter
 
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  • #2
Think the image I handcrafted hastely attached could explain it.
Believe there are two diffraction grating layers, and for the 90 degree rotation from one another, you'd see the light splitting at first into 3 rays diverging, and each ray of that splits again at the second diffraction grating layer, into 3, this time vertically instead of horizontally.
The diffraction gratings in the image are of a single axis, that video shows a double axis diffraction.

There could also be polarization to be taken into account, though. Frankly I don't know how the laser in the video was built.
 

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Related to Two Diffraction Gratings - Rotation

1. What is a diffraction grating and how does it work?

A diffraction grating is an optical component that is used to separate light into its component wavelengths. It consists of a large number of closely spaced parallel grooves or lines on a surface. When light passes through the grating, it is diffracted or bent at different angles depending on its wavelength, resulting in a spectrum of colors. This process is known as diffraction and is based on the principles of interference.

2. What is the purpose of rotating two diffraction gratings?

The rotation of two diffraction gratings allows for the interference patterns produced by the gratings to be manipulated and studied. By rotating one grating relative to the other, the spacing and angle between the grooves can be changed, resulting in different interference patterns. This can be used to measure the wavelength of light, as well as study the properties of light and its interactions with matter.

3. How do the properties of the gratings affect the interference pattern?

The properties of the gratings, such as the spacing between the grooves and the angle at which they are cut, determine the characteristics of the interference pattern. The spacing between the grooves affects the angle at which the diffracted light is dispersed, while the angle of the grooves affects the intensity and contrast of the interference pattern. A larger spacing between the grooves will result in a wider dispersion of the light, while a greater angle of the grooves will result in a more intense and distinct pattern.

4. What are some practical applications of rotating two diffraction gratings?

Rotating two diffraction gratings is used in a variety of scientific and technological applications. It is commonly used in spectroscopy to analyze the composition of materials, as well as in the production of holograms and other optical devices. It is also used in astronomy to study the spectra of distant stars and galaxies, and in telecommunications for wavelength-division multiplexing.

5. Are there any limitations to using two diffraction gratings?

While two diffraction gratings are a powerful tool for studying light and its properties, there are some limitations to their use. One limitation is that the gratings must be carefully aligned and controlled in order to produce accurate and consistent results. Additionally, the gratings can only disperse light up to a certain wavelength, and may not be suitable for use with very short or very long wavelengths. Finally, the quality and precision of the gratings can affect the accuracy and clarity of the interference patterns produced.

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